Opera House staff serenade architect

Staff at the Sydney Opera House have sung Happy Birthday to 90-year-old Jorn Utzon, the Danish architect who created the famous harbourside building.

About 250 staff gathered in the concert hall of the white-tiled, sail-shaped building Utzon designed half a century ago. The Sydney Symphony Orchestra provided the backing music.

Utzon began work on the Opera House in 1957. He quit the project in 1966 following a storm of controversy over budget blow-outs and his artistic vision.

Before it opened in 1973, critics likened the white sails of the now world-renowned building to "albino turtles mating" and "nuns packing into a scrum".

Utzon has never seen it completed.

In 1999, he renewed his involvement with the Opera House after he was asked to work on refurbishing the interiors - most of which are not how he designed them and are acknowledged to have inadequate acoustics.

Opera House chief executive Richard Evans said staff wanted to celebrate Utzon's milestone birthday in a special way given his connection to the building.

"The relationship between the man and the building has extended for more than 50 years and Jorn is still adding to its potential," he said.

The singing was videotaped and will be sent to the Utzon, who lives in Denmark.

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